Network devices can be virtualized to simplify the network structure and to lower the management complexity. For example a plurality of network devices, such as switches, may be connected together and virtualized as a single network device. Such technology is may be referred to as a stacking system. A stacking system may be managed as if it were a single device and acts as a single device, from the perspective of external devices. The stacking system thus includes a plurality of physical member devices, and may act as if it was a single physical device including the ports of all of its member devices. Hardware resources and software processing capacities of the network devices can be integrated in this virtualization technology so that the network devices can interoperate with each other, and be managed collectively.
The Intelligent Resilient Framework (IRF) proposed by the H3C Corp., is one example of a stacking system in which at least two network devices (e.g., Ethernet switches) are connected together through virtualization in software and configured as necessary and then virtualized into a “distributed device”.